This Core Unit will assist the individual Research Projects by serving four general functions: 1) Analyzing expression of globin gene vectors in primary erythroid cultures and transplanted animals using both flow cytometric and molecular methods; 2) Maintaining colonies and testing globin vectors in thalassemic and sickle cell mice; 3) Preparing CD34+ cells from humans and baboons for transduction studies; 4) Producing and characterizing retrovirus vector packaging lines for titer and stability. or Project 1. 1) Analyze expression of retrovirus vectors for globin and trans- activating genes in primary mouse and human erythroid cultures and transplanted mice; 2) Provide animals and analyze expression of globin and trans-activating vectors in thalassemic and sickle cell mice; and 3) Produce retrovirus vector packaging lines for the globin, insulator, and trans- activating constructs. For Project 2: 1) Analyze expression of human foamy virus vectors for globin genes in primary mouse, baboon, and human erythroid cultures and transplanted mice and baboons; 2) provide animals and analyze expression of globin vectors in thalassemic and sickle cell mice; and 3) Prepare human and baboon CD34+ cells for transduction and transplantation studies. For the next project: 1) Analyze expression of deltaAd.AAV vectors for globin genes in primary mouse and human erythroid cultures and transplanted mice; and 2) Provide animals and analyze expression of globin vectors in thalassemic and sickle cell mice. For the next project: 1) Analyze expression of retrovirus vectors for globin genes in primary mouse erythroid cultures and transplanted mice; 2) Provide animals and analyze expression of globin vectors in transplantation studies; and 4) Produce retrovirus vector packaging lines for selection constructs. The last project: Prepare baboon CD34+ cells for transduction and transplantation studies.